1. Field of the Invention
The present invention relates to a welding gun. More specifically, the present invention relates to a welding gun (clamp welding gun) that welds in a state in which a work is sandwiched between a pair of electrode tips.
2. Related Art
Conventionally, among this type of welding gun, there has been a welding gun called an X gun. For example, an X gun 101 is of a structure in which two like structural members are joined at middle parts thereof, and are made to open and close like scissors around a fulcrum portion 100 joining the two structural members, as shown in FIG. 1. More specifically, a pair of electrode tips 121, 141 mounted to leading ends of a pair of gun arms 120, 140, respectively, that extend from the fulcrum portion 100 forward are made to open and close by a servo motor 172 provided more rearward than the fulcrum portion 100, whereby a force is applied to sandwich a work between the pair of electrode tips.
A conventional X gun is a so-called servo gun that uses a servo motor in the drive source thereof.
Furthermore, among welding guns (clamp welding guns), there has conventionally been a welding gun of guide track type. Welding guns of guide track type include a fixed gun arm that is fixed to a gun bracket, an arm holder having a guide pin that is moveable along a guide track formed in the gun bracket, a mobile gun arm that opposes the fixed gun arm, and a pressure cylinder (air cylinder) mounted to the gun bracket. Furthermore, the mobile gun arm is connected to the arm holder, and the mobile arm is made to open and close via the arm holder by the pressure cylinder (e.g., refer to Japanese Unexamined Patent Application, Publication No. H11-245051).
A conventional welding gun of guide track type is a so-called air gun, which uses an air cylinder in the drive source.